1. Technical Field
The present invention relates to a polarizing element, a method for manufacturing the same, a projection type display, a liquid crystal device, and electronic apparatus.
2. Related Art
A variety of electro-optical apparatuses use a liquid crystal device as a light modulation device. In widely known liquid crystal devices, a liquid crystal layer is provided between a pair of substrates opposing each other. Additionally, it is common for such a liquid crystal device to include a polarizing element inputting predetermined polarized light to the liquid crystal layer and an alignment film controlling the alignment of liquid crystal molecules when no voltage is applied.
Among known polarizing elements, there are a film polarizing element and a wire-grid polarizing element. The film polarizing element is produced by extending a resin film containing iodine or a dichroic dye in a single direction to allow molecules of iodine or the dichroic dye to be aligned in the extension direction. The wire-grid polarizing element is formed by densely laying nano-scale metal thin wires on a substrate having transparency.
The wire-grid polarizing element is made of an inorganic material. Thus, due to its excellent thermal resistance, the wire-grid polarizing element is particularly suitable for use as a thermally-resistant constituent member, such as a polarizing element for a light valve of a liquid crystal projector. Exemplary wire-grid polarizing elements are disclosed in JP-A-2007-148344, JP-A-60-230102, and JP-A-2006-3447, for example.
JP-A-2007-148344 discloses a method in which a metal material is deposited on ridges and valleys formed on a substrate from an oblique direction by evaporation or sputtering so as to use the deposited metal fine particles as metal thin wires instead of a conventional method of forming metal thin wires by etching and patterning a metal film. According to the document, the method enables appropriate metal thin wires to be formed without the disadvantages of corrosion in etching a metal material, and the formation of unwanted wire shapes due to reattaching of etched particles or the like.
In JP-A-60-230102 and JP-A-2006-3447, a conductive substance such as metal is evaporated to the protruded portions of a substrate from two directions, and the deposited metal fine particles are used as metal thin wires.
The techniques disclosed in these documents, however, have the following problems.
In JP-A-2007-148344, the metal material is deposited on the substrate on which the metal thin wires are formed by using a slant evaporation method, and preferably ion-beam sputtering, so as to form the metal thin wires, as described above. The method disclosed in JP-A-2007-148344, however, causes size variations in the formed metal thin wires because the distances from a material source of the metal material to various locations on the surface of the substrate differ. The size variations cause parameters, such as a distance between the metal thin wires and the width and height of the metal thin wires, which are closely related optical characteristics of the polarizing element, to vary. As a result, the polarizing element does not exhibit uniform optical properties as a whole.
JP-A-60-230102, and JP-A-2006-3447 do not mention a film-forming amount of the metal thin wires to be formed, and also do not consider the problem caused by the size variations in the formed metal thin wires.